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Abstract
Most greenhouse operators were unconcerned about warnings of limited fuel supplies until the “oil crisis” of 1973. Suddenly everyone was concerned over increasing prices of oil and natural gas, and more critically over their possible inability to obtain an adequate, steady supply of fuel. Prices increased regularly thereafter but until recently, fear over an adequate supply diminished.
Abstract
A survey of floricultural education was conducted for presentation at an International Horticultural Congress Workshop in Aug. 1986. Based on discussion at the workshop, data collected were double-checked with contact persons at each college or university, and the revised data are presented herein (Table 1).
Abstract
The apparent mutation (“mutation”) incidence in rooted cuttings of 5 clones of the garden chrysanthemum treated with 32P was determined. The apical buds were pinched off at 3 different times in relation to treatment with doses of 0, 25, 50, and 100 µc of 32P per plant. The 5 clones varied in response to 32P levels, but 25 µc of 32P per plant was most effective for inducing “mutations” and growth abnormalities. Change in flower color was the most frequently observed “mutation". Apical bud removal did not affect the “mutation” rate. Chromosome counts in root tips showed that the parent plants had either 54 or 56 chromosomes, while “mutants” had from 3 less to the same number of chromosomes as the parent clones.
Abstract
The genus Cyclamen is a member of the Primulaceae, yet speciation of individual members can be confusing. Cyclamen are very diverse, with several species widely distributed throughout the Mediterranean countries and others indigenous only to specific islands or mainland areas (2, 3). Their foliage is extremely variable. Within a single species leaves may range from orbicular to cordate with entire to dentate margins, and with or without gradations of silver-gray zonal patterns. Flowers may be scented or odorless and range in color from white to deep pink. They either precede or arise after the foliage and reach anthesis during autumn, winter or spring (3, 10). The species persicum is uniquely different in that its fruited peduncles haphazardly bend and twist instead of coiling back to the crown. The coiling may facilitate seed dispersal by ants, but C. persicum has lost the coiling characteristic even though it shares this dispersal vector (5).
Abstract
The effects of negative air ions from a high voltage electrical discharge unit on growth and development of 9 plant species were studied in growth chambers and/or in the greenhouse. Treatments consisted of ionization during either the light or dark period, as well as untreated controls. In growth chambers, plants grown in ionized air had significantly greater fresh weights in 13 of 16 instances, but were relatively unaffected in dry weights. Ionization treatments in the greenhouse were less effective but treated plants showed increases in tobacco plant height, geranium stem length and lettuce leaf number.
Abstract
Six-week treatment at a 13°C soil temperature initiated at the 4- and 6-leaf stages most effectively advanced flowering of Cyclamen persicum Mill. cvs. Mayer Reinweiss and Rosa von Zehlendorf-Tas. Stage of flower bud development immediately after treatment of 13°, 18.5, 24.0 and 29.5°C soil temperatures was more advanced, and mean flower bud number increased with each decrease of 5.5°C in soil temperature. At age 9 months, mean days to flower was lower and mean number of flowers per plant was higher with each decrease of 5.5°C in soil temperature. Plants treated at the 6-leaf stage flowered earlier and produced more flowers than those treated at the 4-leaf stage. The 9-month-old plants which had been treated at the 6-leaf stage were generally more advanced vegetatively than those treated at the 4-leaf stage, but the effect of soil temperature treatment on vegetative growth was negligible.
Abstract
The relationship between water extraction (1:1.5) values and nutrient uptake in geranium (Pelargonium × hortorum Bailey) growing in moss peat (peat), bark, or moss peat and soil media was investigated. Nitrogen, P, and K fertilizers were incorporated in increments in the starting media and applied again in solution, about at the crop midpoint. Desirable nutrient N(NH4 +-N + NO3 --N), P(H2PO4 --P) and K(K+) values (DV) from media analysis at the start of the experiments (MDV) and midway to flowering (FDV) also were calculated from regression equations on the basis of maximum growth rates, maximum dry weight production at midharvest, and final harvest. The relationships between plant uptake of N, P, and K and the water extract concentrations were generally very good, except for K in bark for both harvests and in peat at the first harvest, and an underestimated P uptake in peat + soil and in bark. The media DV obtained using growth data were broadly similar to those using plant dry weight data, although somewhat lower for N during the early growing period.
Abstract
A system for greenhouse soil temperature control was designed which combines a moderately wide range of soil temperature above and below air temperature, whole-plot replication, and relatively high numbers of plants per treatment The apparatus was developed for studies involving Cyclamen persicum Mill., but also should be useful for studies of other crops or plant diseases.
Abstract
Gibberellin (GA3) treatment of 6 cyclamen cultivars accelerated flowering 28 to 35 days and increased simultaneous flower production per plant up to 100%. Leaf size, leaf count, and plant size were not altered by GA3. A single spray of 50 ppm GA3 applied 60 to 75 days prior to desired time of bloom is suggested to promote more accurate, efficient scheduling of cyclamen crops.